class Feed def initialize(type, account) @type = type @account = account end def get(limit, max_id = nil, since_id = nil) max_id = '+inf' if max_id.blank? since_id = '-inf' if since_id.blank? unhydrated = redis.zrevrangebyscore(key, "(#{max_id}", "(#{since_id}", limit: [0, limit], with_scores: true).collect(&:last).map(&:to_i) # If we're after most recent items and none are there, we need to precompute the feed if unhydrated.empty? && max_id == '+inf' && since_id == '-inf' PrecomputeFeedService.new.call(@type, @account, limit) else status_map = Status.where(id: unhydrated).with_includes.with_counters.map { |status| [status.id, status] }.to_h unhydrated.map { |id| status_map[id] }.compact end end private def key FeedManager.instance.key(@type, @account.id) end def redis $redis end end